Arc welding device



J. W. DAWSON ARC WELDING DEVICE Filed Oct. 11, 1940 April 28, 1942.

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INVENTOR.

JOHN W. DAwsoN,

Patented Apr. 1942 UNITED STATE ARC WELDING DEVICE John W. Dawson,Anbnrndale, Mala, assignor to Baytheon Manufacturing Company, Newton,Mast, a corporation of Delaware 7 Application October 11, 1940, SerialNo. scones- 9 Claiml. (01. 219-4) This invention relates to an arcwelding device, particularly as applied to the invention as describedand claimed .in the copending application of Laurence K. Marshall andJohn W. Dawson on Arc welding system and method," filed simultaneouslyherewith. In said application there is described and claimed a system inwhich an arc is dispersed by means of magnetic fields over relativelyextended areas of two members to be welded, whereby said surfaces areheated and,

then moved into welding engagement with each other. i Y An object ofthis invention is to produce a device in which the proper movement ofwork pieces in an arc welding system is produced by the reaction of suchmagnetic fields.

Another object is to reverse the polarity of opposing pole pieces toproduce attraction and repulsion thereof for securing correspondingmotion of the parts of the device.

A further object is to produce the foregoing actions by passing the arccurrent through the coils which are used to set up the magnetic fields.

The foregoing and other objects of this invention will be bestunderstood from the following-- description of exemplifications thereof,reference In the drawing, two metal bodies I and 2, which are shown inthe form of tubes or pipes, are to be welded to each other. along theiradjacent edges so as to, form a continuous tube or pipe. The pipes and 2are held spaced apart so as to provide an annular gap 2' in which an arcis to. be established. A rod 3 of magnetic material 'is inserted insidethe pipes and 2 so as to extend past the gap 2' to a point substantiallybeyond said gap. The rod 3 is preferably coated with a refractoryinsulating material to prevent the arc current from flowing through therod 3 and to provide a refractory surface for withstanding the heat ofthe arc. Surrounding the pipes I and 2 respectively are two magneticshells I and 5. These shells are provided with aligned openings 0 and l.

and 8 and 9, respectively, so that the pipes and 2 may be insertedtherein. The edges of the openings 6, I, 8 and 9 provide pole pieces 24,25, 20 and 21, respectively. In order to energize said pole pieces,annular coils I0 and H are placed: 5.

respectively in the inner annular space provided in the magnetic shellsl and 5. If desired refractory washers l0 and II may be placed at oneend of each of the coils l0 and II to shield and protect said coilsagainst the heat generated by the arc in the gap 2'. Also the faces ofthe Pole pieces 25 and 21 may be coated with refractory material for thesame purpose. The terminals of the coils l0 and H are provided withleads |2, II, M and I5, respectively, "said leads passing throughinsulating bushings to the exterior of the shells l and 5.

The shell 5 is held in a stationary position by being mounted upon apair of base members |6||i. These members also carry a clamping ring ilin which the pipe 2 may be securely fastened. The shell I, however, ismovable and carries a clamping ring |8 in which the pipe I may besecurely held. The clamping ring [8 moves in a stationary guide memberl9 provided with a pair of stop shoulders 20-20. In order to tend tomake the shell 4 and the pipe I move toward the shell 5 and the pipe 2,a compression spring 28 may be interposed between the guide member I!and the shell 4.

In order to establish and maintain the arc in the gap 2', a source ofarc current 2| is provided.

This source may supply current of any suitable nature which may be inthe form of direct current or alternating current,'or any specializedcurrent form particularly adapted for the purpose for which it is to beused. In the present arrangement, however, I prefer to have the source2| supply direct current. One terminal of the source 2| is connected bya conductor 22 to the pipe 2. The other terminal of said source isconnected through a reversing switch 23 through the coils II and III inseries. The lead 12 for the coil I is electrically connected to the.pipe I.

If necessary a condenser 29 may be connected across the reversing switch23 in order to avoid sparking or arcing at the contacts of said switch.

With the switch 23 in its open position or with the source-2|deenergized, the spring 28 will cause the adjacent ends of the pipes and2 to contact each other. When the source 2| is energized and the switch23 is closed in the position as shown, current will flow from the source2| through one side of the reversing switch 23, conductor H, coilconductor IS, the other side of said reversing switch 23, conductor l3,coil Ill, conductor l2, pipe I, pipe 2, conductor 22, back to the otherside of said source 2|. The calls l0 and H are wound in'such a:direction as .tween which the discharge passes.

-with the coils I and II. current supply may be chosen for the sourcesto make the adjacent pole pieces 25 and 21 the same polarity under theseconditions. These pole pieces, therefore, will exert a strong repulsiveforce upon each other, and therefore the shell 4 carrying the pipe Iwill be moved away from the shell 5 and the pipe 2 until the ring I3contacts the stop shoulders 20-20. Due to this motion the adjacent endsof the pipes I and 2 will be separated, whereby an arc will be initiatedbetween said adjacent ends. An "arc in the sense as used in thespecification and claims is an electrical space discharge which occursbetween two separated surfaces of suflicient intensity to producesubstantial heating Of the surface be- As pointed out in said copendingapplication, the pole pieces 25 and 21 produce a flux passing radiallythrough the gap 2', which causes a dispersion of the arc throughout saidgap, probably by causing the arc to'move at high speed along said gap.The

are is permitted to continue until the adjacent surfaces of the pipes Iand 2 have been heated to the proper temperature.' Thereupon the switch23 is moved so as to reverse the connections to the coil II. Preferably,in addition to the condenser 29, the switch 23 is of the quickactingtype so asto avoid the tendency for an arc to form across the contacts'of said switch.

Upon operation of the reversing switch 23, the

arc in the gap 2' will tend to be extinguished and the fields in themagnetic shells 4 and 5 will tend to disappear. However the spring 28will move the adjacent ends of the pipes I and 2 into engagement witheach other. The pressure which the spring 28 exerts may be quite slight.

However, upon the reversal of the switch 23, the

. projects a slight distance beyond the outer faces of the shells 4 and5, and therefore the attraction of the poles 25 and 21 will force theheated ends of the pipes I and 2 into sufllciently energetic engagementwith each other to produce complete welding of said adjacent surfaces.-

Instead of having the arc current flow through the coils I0 and II, saidcoils may be separately energized, as indicated in Fig. 2. In thisfigure the source of arc current 2| is connected directly between thepipes I and 2. A separate source of magnetizing current 30 is connectedin series Any suitable type of II and 30.

In the arrangement shown in Fig. 2, the are between the pipes I and 2may be initially started in any suitable manner, as, for example, bymanually bringing said pipes into momentary engagement with each other.Under these conditions, the spring 28 need not be used. As in the caseof Fig. l, the repulsion between the adjacent pole pieces will force thepipes I and 2 apart and maintain them in separated position throughoutthe heating period. Upon reversal of the switch 23, the pipes I and 2may remain in their separated position during such reversal.

However, when the field, due to the coil III, has

vention is not limited to the particular details as described above asmany equivalents will suggest themselves to those skilled in the art. Itis accordingly desired that the appended claims be given'a broadinterpretation commensurate with the scope of the invention within theart.

What is claimed is:

l. A welding system. for welding two surfaces spaced apart comprisingtwo magnetic members adapted to be secured to said two work members,said magnetic members having adjacent pole pieces, means for heatingsaid surfaces, and means for energizing said pole pieces, while saidsurfaces are spaced apart, with opposite polarities to force saidsurfaces together into welding engagement with each other.

2. A welding system for welding two surfaces spaced apart comprising twomagnetic members adapter to be secured to said two work members, saidmagnetic members having adjacent pole pieces, means for energizing saidpole pieces with the same polarity to move said work pieces apart totheir spaced positions, means for heating said surfaces, and means forreversing the polarity of said pole pieces with respect to each other toforce said surfaces together into welding engagement with each other.

3. A welding system for welding two surfaces spaced apart to form an arcgap comprising two magnetic members adapted to be secured to said twomembers, said magnetic members having adjacent pole pieces adjacent saidare gap, means for energizing said pole pieces with the same polarity tomove said work pieces apart to their spaced positions and to produce amagnetic field transverse to said arc gap, and means for establishing anarc in said are gap.

4. A welding system for welding two surfaces spaced apart to forman arcgap comprising two magnetic members adapted to be secured to said twowork members, said magnetic members having adjacent pole pieces meansfor establishing an arc in said are gap, and means for energizing said/pole pieces with opposite polarities while said surfaces are spacedapart, to force said surfaces together into welding engagement with eachother.

5. A welding system for welding two surfaces spaced apart to form an arcgap comprising two magnetic members adapted to be secured to said twomembers, said magnetic members having adjacent pole pieces adjacent saidare gap, means for energizing said pole pieces with the same polarity tomove said work pieces apart to their.

spaced positions and to produce a magnetic fleld transverse to said aregap, meansfor establishing an arc in said are gap, and means forenergizing said pole pieces with opposite polarities to force saidsurfaces together into welding engagement with each other.

6. A welding system for welding two work members with surfaces spacedapart to form an arc gap, comprising two magnetic members adapted to besecured to said two work members, said magnetic members having adjacentpole pieces, a source of arc current for establishing an arc in said aregap, windings for energizing said pole pieces with the same polarity tomove said work pieces apart to their spaced positions, said windingsbeing connected in series with said source, and means for.reversing thepolarity of said windings with respect to each other to reverse thepolarity of said pole pieces and force said surfaces together intowelding engagement with each other.

7. In a welding system for welding two work members with surfacesspacedapart to form an arc gap, means for moving said work piecestogether, comprising two magnetic members adapted to be secured to saidtwo work members, said magnetic members having adjacent pole pieces,means for energizing said pole pieces with the same polarity to movesaid work pieces apart to their spaced positions, means for establishingan arc in said arc gap, and means for reversing the polarity of saidpole pieces with respect to each other to force said surfaces togetherinto welding engagement with each other.

8. A welding system for welding two surfaces spaced apart'comprising twomagnetic members adapted to be secured to said two work members, saidmagnetic members having adjacent pole pieces, means for heating saidsurfaces, and means for energizing said pole pieces while said surfacesare spaced apart to force said surfaces together into welding engagementwith each other.

9. A welding system for welding two surfaces spaced apart to form an arcgap comprising two magnetic members adapted to be secured to said twowork members, said magnetic members having adjacent pole pieces, meansfor establishing an arc in said arc gap, and means for energizing saidpole pieces while said surfaces are spaced apart to force said surfacestogether into weldin engagement with each other.

JOHN W. DAWSON.

